Pathname#version: only parse version from file basename

i.e. Ignoring the file's directory for version parsing.

Closes Homebrew/homebrew#50568.

Signed-off-by: Xu Cheng <xucheng@me.com>

Library/Homebrew/extend/pathname.rb

@@ -239,7 +239,7 @@ class Pathname
   # @private
   def version
     require "version"
-    Version.parse(self)
+    Version.parse(basename)
   end
 
   # @private